| Zugriffsnummer | 52287 |
| Dokumenttyp | Zeitschriftenartikel |
| Peer Review | mit Peer Review |
| Sprache | Englisch |
| Titel | B1-MRF: Large dynamic range MRF-based absolute mapping in the human body at 7T |
| Autor(in); Institution |
Flassbeck, Sebastian; Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, New York, USA
Gatefait, Constance G. F.; 8.1, Biomedizinische Magnetresonanz, PTB-Berlin
|
| Quelle/Jahr | Magnetic Resonance in Medicine: 92 (2024), 6, 2473 - 2490 |
| ISSN | 0740-3194 (print) ; 1522-2594 (online) |
| DOI | |
| Verlag | New York, NY: Wiley / ISMRM |
| Freie Schlagworte | 7 Tesla ; B+1 mapping ; body MRI ; MRF ; ultra high field MRI |
| Zusammenfassung | Purpose This study aims to map the transmit magnetic field (B+1) in the human body at 7T using MR fingerprinting (MRF), with a focus on achieving high accuracy and precision across a large dynamic range, particularly at low flip angles (FAs). Methods A FLASH-based MRF sequence (B1-MRF) with high B+1 sensitivity was developed. Phantom and in vivo abdominal imaging were performed at 7T, and the results were compared with established reference methods, including a slow but precise preparation-based method (PEX), saturated TurboFLASH (satTFL), actual flip angle imaging (AFI) and Bloch-Siegert shift (BSS). Results The MRF signal curve was highly sensitive to B+1 , while T1 sensitivity was comparatively low. The phantom experiment showed good agreement of B+1 to PEX for a T1 range of 204–1691 ms evaluated at FAs from 0° to 70°. Compared to the references, a dynamic range increase larger than a factor of two was determined experimentally. In vivo liver scans showed a strong correlation between B1-MRF, satTFL, and RPE-AFI in a low body mass index (BMI) subject (18.1 kg/m2). However, in larger BMI subjects (≥25.5 kg/m2), inconsistencies were observed in low B+1regions for satTFL and RPE-AFI, while B1-MRF still provided consistent results in these regions. Conclusion B1-MRF provides accurate and precise B+1 maps over a wide range of FAs, surpassing the capabilities of existing methods in the FA range < 60°. Its enhanced sensitivity at low FAs is advantageous for various applications requiring precise B+1 estimates, potentially advancing the frontiers of ultra-high field (UHF) body imaging at 7T and beyond. |
| Kostenfreier Zugang | Open Access Hybrid |
| Rechteinformation | CC BY 4.0 ; Creative Commons Attribution 4.0 License |
| Förderinformationen (1) |
Förderername: Deutsche Forschungsgemeinschaft (DFG)
Förderer ID: 0000 0001 2096 9829 Förderprogramm: GRK 2260: BIOQIC Titel der Förderung: MRF Based B1+ mapping Förderungsnummer: PV-81033, SCHM2677/4-1 |
Zitierung
Lutz, M., Aigner, C. S., Flassbeck, S., Krüger, F., Gatefait, C. G. F., Kolbitsch, C., Silemek, B., Seifert, F., Schäffter, T., & Schmitter, S. (2024). B1-MRF: Large dynamic range MRF-based absolute mapping in the human body at 7T. Magnetic Resonance in Medicine, 92(6), 2473–2490. https://doi.org/10.1002/mrm.30242